The necessity for providing strain relief for electrical cables of whatever cross-section is well known in the art as are numerous arrangements for providing that relief. Were no means for restraining the conductors of a cable provided at their point of connection with associated terminals or electrical equipment, the soldered or other conductor terminations would be constantly vulnerable to interruption by stresses applied to the cable. To safeguard against such separation of cable conductors from their component terminals, a number of strain relief devices have been provided, ranging from a simple clamp for fixedly holding the cable relative to its terminating component to more complex arrangements such as that disclosed, for example, in U.S. Pat. No. 4,080,038 of J. C. Latla et al., issued Mar. 21, 1978. The strain relief arrangement there shown comprises a pair of elongated members arranged on each side of a flat ribbon cable connector which are snapped inwardly to urge and hold the cable conductors in contact with the connector contacts. This arrangement, although effective to restrain the conductors and to provide relief against external stress, is manifestly complex and by adding a number of moving parts, adds substantially to the cost of the connector assembly. From the latter viewpoints alone, a simple clamping arrangement in which opposing flanges clamp the ribbon cable therebetween presents significant advantages.
For the most part such simple clamping arrangements have in the past adequately performed their strain relief function. By exerting clamping pressure on each side of a ribbon cable, the cable is effectively prevented from any outward movement, thereby, in turn, preventing stress on the conductor terminations. This very pressure, however, although restraining the conductors, has in the past caused problems and, on occasion, caused a shorting of conductors with the clamping means. The plastic ribbon material in which the conductors are embedded, typically, polyethelene-terephthalate, is subject to pressure caused cold flow. As a result, either during assembly or after installation, a high risk is presented that the clamping pressure will cause an extrusion of the plastic cable insulation from a conductor or conductors with a concomitant shorting of the conductors with the clamp. It is to this problem, together with the objective of simplifying its manufacture, that the strain relief apparatus of this invention is directed.